1. Objective: To find the percent composition of water in an unknown hydrate.
2. Materials: Goggles, apron, evaporating dish, hot plate, and stirring rod
get the mass of a evaporating dish, put a sample of the hydrate onto the evaporating dish and mass the dish with hydrate.
Put the dish with hydrate on the hot plate on high heat.
Break up any clumps that form during the heating process.
Observe any color changes visible and take off heat after 5 min.
Let the sample cool and re-mass it.
|Sample ID # |Mass in grams (g) | |Mass of Evaporating dish |47.08 | |Mass of Evaporating dish and hydrate |48.14 | |Mass of hydrate |1.06 | |Mass of Evaporating dish and anhydrous salt |48.02 | |Mass of anhydrous salt |0.4 | |Mass of water evaporated |0.12 | |True % of water for sample |10.61% |
5. Data analysis:
1. You must allow the evaporating dish to cool because you could burn yourself or others and you could damage the scale because the evaporating dish is so hot.
2. If the anhydrous salt is not measured immediately after cooling than the anhydrous salt will absorb water from the air around it, which will...